Heterointerface Engineering of Broken-Gap InAs/GaSb Multilayer Structures

Abstract

Broken-gap InAs/GaSb strain balanced multilayer structures were grown by molecular beam epitaxy (MBE), and their structural, morphological, and band alignment properties were analyzed. Precise shutter sequence during the MBE growth process, enable to achieve the strain balanced structure. Cross-sectional transmission electron microscopy exhibited sharp heterointerfaces, and the lattice line extended from the top GaSb layer to the bottom InAs layer. X-ray analysis further confirmed a strain balanced InAs/GaSb multilayer structure. A smooth surface morphology with surface roughness of ∼0.5 nm was demonstrated. The effective barrier height -0.15 eV at the GaSb/InAs heterointerface was determined by X-ray photoelectron spectroscopy, and it was further corroborated by simulation. These results are important to demonstrate desirable characteristics of mixed As/Sb material systems for high-performance and low-power tunnel field-effect transistor applications.

Two-dimensional WS2/MoS2 heterostructures: properties and applications

“…Two-dimensional (2D) materials have been one of the most widely scientifically investigated subjects because a number of uncommon physical events arise when thermoelectric interaction is limited to a plane. [1][2][3] van der Waals (vdWs) heterostructures composed of layered materials have attracted extensive focus due to their superb properties such as smooth heterostructure interface, 4,5 ultrafast carrier transport, 6 and highly gate-tunable bandgap. [7][8][9] With the continuous development of 2D material fabrication technology, transition metal dichalcogenides (TMDs) have been studied in more detail.…”

Structural, morphological and magnetotransport properties of composite semiconducting and semimetallic InAs/GaSb superlattice structure

“…During the growth of this structure, a GaAs-like interfacial layer at any interface (GaSb-on-InAs or InAs-on-GaSb) must be prevented. 2 In the shutter sequencing during growth ( Fig. 2b), the Sb 2 flux was left open after the growth of GaSb.…”

“…Such expansion implies that the wavefunction is continuous across each interface. Moreover, the plane wave expansion aids in reducing the coupled differential equations to a more straightforward eigenvalue problem, which can be solved numerically, although the size of the matrix increases to (8 Â (2N + 1)) 2 . In this work, we let N = 30(100) for the simplified (realistic) structure, as described in ref.…”

“…Arsenide and antimonide-based semiconductor heterostructures have attracted attention for many years as technological cornerstones for emerging, high-performance nanoscale devices. [1][2][3][4][5][6][7][8][9][10][11][12][13] In particular, extensive research efforts have been dedicated to type-II broken-gap InAs/GaSb heterostructures [8][9][10][11][12][13] wherein the superlattice (SL) periodicity can modify the band structure, resulting in either a semiconducting (energy gap, E G 4 0) or semimetallic (E G r 0) material system. It has been widely reported that long-period InAs/GaSb SLs exhibit semimetallic behavior whereas shorter period SLs exhibit semiconducting behavior.…”

“…It has also been reported that the InAs/GaSb interface can be designed to exhibit either an InSb-like interface or both InSb-and GaAs-like interfaces in GaSb/InSb or GaSb/GaAs-like/ InAs/InSb-like/GaSb SL structures. 2 In addition, the enhanced surface segregation of antimony (Sb) and In atoms, as compared to arsenic (As) and gallium (Ga), makes the InAs/GaSb heterostructure extremely challenging to realize via epitaxial growth. Moreover, this segregation effect can introduce interfacial disorder that could detrimentally affect the material's electronic properties.…”